Process for producing maltooligosaccharide derivatives

Abstract

A polyacyl maltooligosaccharide derivative which is a precursor of a maltooligosaccharide derivative having modified groups at the 6-position or 4- and 6-positions of non-reducing end glucose unit and being effectively used as a substrate for measuring α-amylase activity, can be produced under mild conditions by crosslinking OH groups in the non-reducing end glucose unit of oligosaccharide with a benzylidene group having an alkoxy group, followed by acylation and treatment with a dilute acid.

What is claimed is: 
     
       1. A process for producing a maltooligosaccharide glucoside of the formula ##STR12## wherein R 1  ' is an acyl group or an optically measurable group releasable from the maltooligosaccharide glucoside by action of an enzyme and which, after being released, absorbs visible or ultraviolet light, is fluorescent, or forms a dye when coupled to a coupler by action of an oxidase or an oxidizing agent; R 4  is an acyl group and m is an integer of 1 to 5; which comprises reacting a glucoside compound of the formula ##STR13## wherein R 1  is hydrogen or an optically measurable group which is releasable from the glucoside compound by action of an enzyme and which, after being released, absorbs visible or ultraviolet light, is fluorescent, or forms a dye when coupled to a coupler by action of an oxidase or an oxidizing agent; and m is as defined above; with a compound of the formula ##STR14## wherein R 2  is a lower alkyl group, R 3  is a lower alkyl group and n is an integer of 1 to 3, to form a cyclic acetal blocking the hydroxyl groups at the 4- and 6-positions of non-reducing end of the glucoside compound of formula; acylating the cyclic acetal reaction product and then decomposing the cyclic acetal with a dilute acid.   
     
     
       2. A process according to claim 1, wherein the reaction of the compound of the formula with the compound of the formula is carried out using an acid catalyst. 
     
     
       3. A process according to claim 1, wherein the acylation is carried out in the presence of a base using as an acylating agent acetic anhydride, acetyl chloride or benzoyl chloride. 
     
     
       4. A process according to claim 1, wherein the compound of the formula is p-anisaldehyde dimethylacetal, veratrum aldehyde dimethylacetal or 3,4,5-trimethoxybenzaldehyde dimethylacetal. 
     
     
       5. A process according to claim 1, wherein the compound of the formula is p-anisaldehyde dimethylacetal.